Trimming mechanism for blind stitch sewing machines



April 30, 1940. H. F. GRUMAN TRIMMING MECHANISM FOR BLIND STITCH SEWING MACHINES Olrgnal Filed April 12, 1937 3 Shee.l,s-S11eeil 1 April 30, 1940. H. F. GRUMAN TRIMMING MECHANISM FOR BLIND STITCH SEWING MACHINES s sheets-sheet 2 Original Filed April l2, 1957 April 30, 1940. H F, GRUMAN 2,199,172

TRIMMING MECHANISM FOR BLIND STITCH SEWING MACHINES Original Filed April 12, i937 3 Sheetsi-Sheet 3 Patented Apr. 30, 1940 TRIMMING MECHANISM FOR BLIND STITCH SEWING MACHINES Horace F. Gruman, St. Louis, Mo.. assigner to Geoffrey Stevenson, BuHalo, N. Y.

Original application April 12, 1937, Serial No.

Divided and this application October Z5, 1937, Serial No. 170,916

25 Claims.

A parent application for Sewing machines, Serial No. 136,466, iiled April 12, 1937.

The principal object of my invention is to provide a trimming mechanism between the hemmer and the needle for trimming the inner edge of the hem immediately prior to the hein being anchored by the blind stitch forming mechanism.

With the above and other objects in view which will more fully appear, the nature of the invention will be more clearly understood by following the description, the appended claims, and the several views illustrated in the accompanying drawings.

In the drawings:

Figure l is a front elevation of a sewing machine constructed in accordance with my invention,

Figure 2 is a partial top plan view thereof,

Figure 3 is an enlarged plan view of the presser foot, showing the ridge forming element, the trimming mechanism, and the stitch forming elements,

Figure 4 is a perspective view of the needle driving mechanism,

Figure 5 is an enlarged front elevation of the movable trimmer.

Figure 6 is an end elevation thereof,

Figure 7 is a rear view of the movable trimmer,

Figure 8 is a detail plan view of the front end of the presser foot, and

Figure 9 is a side elevation thereof.

The sewing machine which embodies my invention includes a. main frame A comprising a standard 5 having upper and lower arms 6, 1 extending laterally from the left side thereof, the free end of the upper arm being provided with a transverse and upwardly opening recess 8 forming a resultant horizontal arm extension 9 and a vertical end wall I0, the left hand end of the arm extension beingformed centrally with a vertical recess II forming resultant front and rear bearing lugs I2, I3. Y

A main shaft I4 extends longitudinally along the upper arm 6 and across the standard 5 and is suitably journaled therein, the left hand end of the shaft extending across the recess II above the arm extension 9 and being journaled in the end wall I0, the arm extension 9 and the end wall III thus cooperating to form an extended bearing for the shaft.

A horizontal presser foot B having an opening l5 is located below the arm extension and is rigidly secured thereto by spacedvertical arms I6, I1. A ridge forming element C is mounted in the lower frame arm 1 for projecting a ridge of hemmed fabric upwardly through the presser foot opening I5 into needle penetrating position.

A horizontal needle shaft Itis journaled in the spacedbearing lugs I2, I3 and is therefore located below and at right angles to the main shaft I4, and directly above the opening I5 of the presser foot B. Attached to the forward end of the needle shaft and projecting towards the left thereof, is a needle arm I9 and attached to said arm is a curved needle 20. .A rock arm 2| which is fixed to the needle shaft intermediate the bearing lugs I2, I3 is driven from the main shaft by an eccentric 22 fixed thereon in the recess 8 and a cooperating pitman 23 which extends up-` wardly vthrough the recess II. Thus, the needle will be reciprocated horizontally over the presser footw opening Il once for each rotation of the main'shaft, the forward or penetrating stroke of the needle being from left to right.

A loop taker 24 and a loop spreader 24 cooperate with the needle to form a line of overedge blind stitches. vThe loop taker reciprocates across the ridge forming means, and the loop spreader reciprocates in a path disposed generally to the right of the vridge forming means. These elements', in themselves, form no part of the present invention, except insofar as they cooperate in the general combination claimed hereinafter, and since their general functions are well known in the art and their specific constructions and drive connections are shown and described in detail in my parent application for U. S. Letters Patent Serial No. 136,466, illed April 12, 1937, further detailed disclosure herein'is thought to be unnecessary. It is deemed suiiicient to state that each time the needle 2l) begins its backward stroke, the loop spreader 24l will pick up the needle' thread loop and carry it forwardly into position to be entered by the loop taker 24 and the loop taker will then continue its forward stroke and position its looper thread loop to be entered by the needle during its next forward stroke.

It is desirable to trim the inner edge of the so end, the presser foot B is provided in front of u the needle path, with an L-shaped opening comprlsing a longitudinal opening 25 and a communicating lateral opening. The lateral opening is formed by a forwardly extending foot portion 28 and a rearwardly extending footportion 21. The under face of the portion 28 incllnes downwardly and rearwardly, and the upper face of the portion 21 inclines downwardly and rearwardly, said upper and lower faces conjointly forming a resultant rearwardly vand downwardly inclined slot 28 forreceiving the nose 29 of a folder 30 which is secured to a bracket arm 3l removably mounted on the front wall of the lower frame arm 1, the folder extending around the rearwardly projecting portion-21. The longitudinal opening 25 is locatedv in front of and in register with the opening I5, and the lateral opening is located on the right hand side of the opening 25. A horizontal ledger blade 32 is seated in a transverse groove 33 formed in the upper face of the foot on the left of the opening 25 and in rear of the nose 29 of the folder, and is adjustably clamped therein by a screw 34, the cutting edge of the vblade preferably projecting slightly into the opening 25 and lying in parallelism with said opening. A horizontal movable blade or knife 35 cooperates with the ledger blade 32 to trim the upt'urned edge of the hem, the movable blade being reciprocable across the rear end of the opening 25, and being provided with a toe or extension 36 which is maintained in yieldable sliding contact with said ledger blade. The cutting edge of the' movable blade inclines rearwardly towards the cutting edge of the ledger blade to provide a shearing cutting action between the blades, and the toe 36 is located at the rear end of the cutting edge of the movable blade. The movable blade is removably attached to a holder 31 byl a longitudinally extending clamp 38 and screw 39, the holder and the clamp being conjointly formed with a dovetailed groove for receiving the blade. The heel of the holder 31 is pivotally connected by a transverse pin 49 to the lower arm 4I of a supporting lever 42 which is fulcrumed on a horizontal stud or bearing 43 fixed to and extending forwardly from a bracket 44t attached to the upper frame arm 8. The upper arm 44 of the lever is pivotally connected by a link 45 to an eccentric pin 46 fixed to the front end of the needle shaft I8. The holder 31 is provided with a rigid and upstanding lever arm 41 which is located intermediate the cutting edge of the movable blade and the pivot 40, and a coil spring 48 is interposed between the arm 41 and the lower arm 4I of the supporting lever 42 and functions to maintain the movable blade in yieldable contact with the ledger blade. The left hand end of the clamp 38 terminates in a guide 49 for the trimmed off strip, the guide being curved downwardly and rearwardly and terminates in close fitting relation to the toe 38. Cooperating with the under face of the presser foot B to'feed'the fabric rearwardly from the trimming mechanism toward and past the needle path is a suitable lower feeding mechanism. This mechanism includes a main 4-motion feed dog II3` and a 4motion diiferential feed dog II4. 'I he main feed dog |I3 includestwo long side sections II5, H6 and a short intermediate section I I1 which operate in the rear portions of the feed slots of the work clamp. 'Ihe side sections are disposed on opposite sides of the presser foot opening I5 and extend forwardly to a point slightly in front of the needle path, but the intermediate section is disposed wholly in rear of the needle path and in rear of said opening.

The differential feed dog includes two long sidel sections and a short intermediate section which operate in the front portions of the feed slots in the work clamp. The side sections are disposed on opposite sides of the presser i'oot opening I5 and extend forwardly to a point' slightly in front of said opening, but the intermediate section |29 cooperates with the foot immediately in front of the opening I5 and its rear end terminates infront of the trimmer ledger blade 32. VThe side sections II5, II8 and IIB, II9 of the feed dogs are arranged in overlapping relation for engaging the body fabric throughout the combined length of both dogs.

A back and forth movement is imparted to the diiferential feed dog II4 during each rotation of the main shaft and its feed stroke can be varied. Similarly, a back and forth movement will be imparted to the main feed dog during each rotation of the main shaft, and its feed stroke also can be varied. Since the feeding mechanisms, in themselves, form no part of 'the'present invention, except insofar as they cooperate in the general combination claimed hereinafter, and since these mechanisms are disclosed in detail in my parent case Serial No. 136,466, led April l2, 1937, and covered in another divisional application for U. S. Letters Patent Serial No. 170,918, filed October 25, 1937, further detailed description herein is thought to be unnecessary.

It will be seen that the edge portion of the hem fold immediately after leaving the hemmer, is directed upwardly by the opening 25 and is then trimmed by the cooperating horizontal cutting elements 32, 35. The trimmed edge portion of the hem fold is then turned down against the body fabric by engaging the bridge on the presser foot between the alined openings 25 and I5 whereby the entire trimmed hem fold will be positioned flat against the body fabric immediately prior to the same being engaged by the ridge forming element C. Immediately thereafter the hem fold will be Joined to the body fabric by the line of blind stitches in which the needle thread loops first enter the body fabric and pass upwardly through the hem fold and are concatenated by a covering thread which is formed into loops overlying the trimmed edge of the hem fold. This produces an extremely flat and covered hem fold.

From the foregoing it will be observed that both the needle and the movable trimmer blade are operated from the needle shaft; that the needle moves from left to right during its forward or penetrating stroke; that the movable blade moves from right to left during its cutting stroke; that the trimming elements arevlocated between the needle and the folder, and that the ridge forming element projects the trimmed hem upwardly into needle penetrating position.

It is of course to be understood that the details of structure and arrangement of parts may be variously changed and modified without departing from the spirit and scope of my invention.

I claim:

l. In a blind stitchv sewing machine, means for joining the edge of a superposed fabric' layer to a base fabric layer comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, and a trimming mechanism 'located in front of the opening for trimming the edge of the superposed layer vprior to said layers being ridged.

2. In a blind stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for reciprocating the needle, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, a trimming mechanism llocated in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, and driving connections between the needle reciprocating means and the trimming mechanism for operating the latter.

3. In a blind stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means forreciprocating the needle, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, said trimming mechanism including a horizontal ledger blade fixed to the foot and a cooperating horizontally reciprocatory movable blade, and driving connections between the needle reciprocating means and the movable trimmer blade for operating the latter.

4. In a blind stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, and a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, said trimming mechanism including a horizontal ledger blade fixed to the foot and a cooperating horizontally reciprocatory movable blade.

5. In a blindstitch sewing machine, means for joining'. the edge of a superposed fabric layer to a base fabric layer comprising a frame having a laterally extending arm, a horizontal presser foot secured to said arm and provided with an opening, a stitch forming mechanism operating entirely above the foot and including a rock shaft and a needle carried thereby for reciprocations across said opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, and a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, said trimming mechanism including a ledger blade and a movable blade, and driving connections between the needle rock shaft and the movable blade.

6. In a blindv stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a frame having a laterally extending arm, a horizontal presser foot secured to said arm and provided with an opening, a stitch forming mechanism operating entirely above the foot and including a rock shaft and a needle carried thereby for reciprocations across said opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, and a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, said trimming mechanism including a horizontal ledger blade fixed to the foot and a cooperating horizontally reciprocatory movable blade, and driving connections between the needle rock shaft and the movable blade. Y

7. In a blind stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a frame having a laterally extending arm, a horizontal presser foot secured to said arm and provided with an opening, a stitch forming mechanism operating entirely above the foot and including a rock shaft and a needle carried thereby for reciprocations across said opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, and a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, said trimming mechanism including a vertical lever fulcrumed intermediate its ends on the frame arm, a horizontal ledger blade fixed to the foot, a cooperating horizontally reciprocatory movable blade connected to the lower arm of said lever, and driving connections between the needle rock shaft and the upper arm of said lever.

8. In a blind stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a frame having a laterally extending arm, a horizontal presser foot secured to said arm and provided with an opening, a stitch forming mechanism operating entirely above the foot and including a rock shaft and a needle carried thereby for reciprocations across said opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, and a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, said trimming mechanism including a vertical lever fulcrumed intermediate its ends on the frame arm, a horizontal ledger blade fixed to the foot, a cooperating horizontally reciprocatory movable blade, a holder for the movable blade pivotally connected to the lower arm of said lever, spring means between the holder and the lever for maintaining the movable blade in yieldable contact with the ledger blade, and driving connections between the needle rock shaft and the upper arm of said lever.

9. In a blind stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, a trimming mechanism located in front oi' the opening for trimming the edge of the superposed layer prior to said layers being ridged, said trimming mechanism including a horizontal ledger blade fixed to the foot and a cooperating horizontally reciprocatory movable blade, and means for reciprocating the needle and the movable blade whereby the penetrating stroke of the needle and the trimming stroke of the blade' will be imparted simultanevously.

10. In a blind stitch sewing machine, means for joining a hem fold to a body fabric comprising a horizontal presser foot having an open-` ing, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hemupwardly through the opening into needle penetrating position, a hemmer located lin-"lfront of the opening, and a trimming mechanism located intermediate the hemmer and the opening for trimming the inner edge of the hem prior to the body fabric and hem being ridged.

11. In a blind stitch sewing machine, means for joining a hem fold to a body fabric comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hem upwardly through the opening into needle penetrating position, said foot being provided with a longitudinal guide slot located in front of and in alinement with the opening therein, a hemmer having its nose positioned to direct the hem into said guide slot, and a trimming mechanism operating across the rear end of the slot for trimming the inner edge of the hem prior to the body fabric and hem being ridged.

12. In a blind stitch sewing machine, means for joining a hem fold to a body fabric comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hem upwardly through the opening into needle penetrating position, said foot being provided with a longitudinal guide slot located in front of and in alinement with the opening therein, a hemmer having its nose positioned to direct the hem into said guide slot, and a trimming mechanism operating across the rear end of the slot for trimming the inner edge of the hem prior to the body fabric and hem being ridged, said trimvming mechanism including a horizontal ledger vblade fixed to the foot at one side of the slot,

and a cooperating reciprocatory blade movable horizontally across said slot.

13. In a sewing machine for joining a hem fold to a body fabric, the combination with a horizontal presser footl having an opening, of a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hem upwardly through the opening into needle penetrating position, a trimming mechanism located in front of the opening for trimming the inner edge'of the hem prior to the body fabric'and hem being ridged, and a lower feeding mechanism including a feed dog cooperating with the bottom of the foot for feeding the fabric from the trimming mechanism to the needle path.

14. In a sewing machine for joining a hem fold to a body fabric, the combination with a horizontal presser foot having an opening, of a stitch forming mechanism operating entirely'above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hem upwardly throughthe opening into needle penetrating position, a trimming mechanism located in front of the opening for trimming the inner edge of the hem prior to the body fabric and hem being ridged, and a lower feeding mechanism for feeding the fabric rearwardly from 'the trimming mechanism to a point in rear of the needle, said feeding mechanism including a main feed dog and a differential feed dog, the latter feeding the fabric rearwardly from the trimming mechanism towards the needle path.

15. In a sewing machine for joining a hem fold to a body fabric, the combination with a horizontal presser foot having an opening, of a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hem upwardly through the opening into needle penetrating position, a hemmer located in front of the opening, a trimming mechanism located intermediate the hemmer and the opening for trimming the inner edge of the hem prior to the body fabric' and hem being ridged, and a lower feeding mechanism including a feed dog cooperating with the bottom of the foot for feeding the fabric rearwardly from the hemmer past the trimming mechanism.

16. In a sewing machine for Joining a hem fold to a body fabric, the combination with a horizontal presser foot having an opening, of a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hem upwardly through the opening into needle penetrating position, a hemmer located in front of the opening, a trimming mechanism located intermediate the hemmer and the opening for trimming the inner edge of the hem prior to the body fabric and hem being ridged, and a lower feeding mechanism for feeding the fabric rearwardly including a main feed dog and a differential feed dog, the latter feeding the fabric from the hemmer and past the trimming mechanism.

17. In a blind stitch sewing machine for joining a hem fold to a body fabric, the combination with a horizontal presser foot, of an voveredge stitch forming mechanism operating entirely above the foot and including a needle mounted for substantially horizontal reciprocations above the foot, means for projecting a ridge of body fabric and a trimmed hem fold into needle penetrating position, a horizontal trimming means located in front of the needle, means for directing the edge portion of the hem fold in a vertical plane to the trimming means, and means located between the trimming means and the needle Afor turning the trimmed edge portion down against the body fabric prior to the formation of said fabric ridge.

18. In a blind stitch sewing machine for joining a hem fold toa body fabric, the combination with a horizontal presser foot. of an overedge stitch forming mechanism operating entirely above the foot and including a needle mounted for substantially horizontal reciprocations above the foot, a loop taker and a loop spreader cooperating with each other and with the needle. means for projecting a ridge of body fabric and a trimmed hem fold into needle penetrating position, the penetrating stroke of the needle being from left to right, said loop spreader reciprocating on the ridge of the ridge forming means and said loop taker reciprocating across the ridge forming means, a horizontal trimming means located in front of the needle, means for directing the edge portion of the hem fold in a vertical plane to the trimming means, and means v formed.

located between the trimming means and the needle for turning the trimmed edge portion down against the body fabric prior to the formation of said fabric ridge.

19. In a blind stitch sewing machine for joining a hem fold to a body fabric, the combination with a horizontal presser foot, of an overedge l stitch forming mechanism operating entirely above the foot and including a needle mounted for substantially horizontal reciprocations above the foot, means for projecting a ridge of body fabric and a trimmed hem fold into needle penetrating position, a hemmer located in front of the ridge projecting means, a horizontal trimming means located between the ridge projecting means and the hemmer. means located in front of the trimming means for directing the edge portion of the hem fold as it leaves the hemmer in a vertical plane to said trimming means, and means located between the trimming means and the needle for turning the trimmed edge portion down against the body fabric prior to the formation of said fabric ridge.

20. In a blind stitch sewing machine for joining a hem fold to a body fabric, the combination with a horizontal presser foot having front and rear openings and a bridge therebetween, of a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the rear opening, a ridge forming element for projecting a ridge of body fabric and hem upwardly through said rear opening into needle penetrating position, a horizontal trimming mechanism for the hem fold operating in front of the ridge forming means including a stationary ledger blade located at one side of the front opening and a cooperating movable blade reciprocal across said front opening, and means for directing the edge portion of the hem fold in a vertical plane to the trimming means, said bridge effecting the turning down of the trimmed hem fold against the body fabric prior to the ridge therein being formed.

21. In a blind stitch sewing machine for joining a hem fold to a body fabric, the combination with a horizontal presser foot having front and rear openings and a bridge therebetween, of a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the rear opening, a ridge forming element for projecting a ridge of body fabric and hem upwardly through said rear opening into needle penetrating position, a hemmer located in front of the ridge forming element. a horizontal trimming mechanism for the hem fold located between the ridge. forming element and the hemmer and including a stationary ledger blade located at one side of the front opening and a cooperating movable blade reciprocal across said front opening, and means for directing the edge portion of the hem fold in a vertical plane to the trimming means, said bridge effecting the turning down of the trimmed hem fold against the body fabric prior to the ridge therein beinl 22. In a blind stitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer and covering said edge comprising a horizontal presser foot having lan opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, a. loop taker and a loop spreader cooperating with each other and with the needle to form concatenated joining and overedge stitches, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, and a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged.

`23. In a blindstitch sewing machine, means for joining the edge of a superposed fabric layer to a base fabric layer comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of said layers upwardly through the opening into needle penetrating position, a trimming mechanism located in front of the opening for trimming the edge of the superposed layer prior to said layers being ridged, and a lower feeding mechanism including a feed dog cooperating with the bottom of the foot for feeding the fabric from the trimming mechanism to the needle path.

24. In a blind stitch sewing machine, means for joining a hem fold to a body fabric comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening, means for projecting a ridge of body fabric and hem upwardly through the opening into needle penetrating position, a hemmer located in front of the opening, and a trimming mechanism located intermediate the hemmer and the ridge projecting means for trimming the edge of the hem fold prior to the body fabric and the hem being ridged.

25. In a blind stitch sewing machine, means for joining a hem fold to a body fabric comprising a horizontal presser foot having an opening, a stitch forming mechanism operating entirely above the foot and including a needle mounted for reciprocations across the opening. means for projecting a ridge of body fabric and hem upwardly through the opening into needle penetrating position, a hemmer located in front of the opening, atrimming mechanism located intermediate the hemmer and the ridge projecting means for trimming the edge of the hem fold prior to the body fabric and the hem being ridged, and a lower feeding mechanism for feeding the fabric rearwardly including a main feed dog and a differential feed dog, the latter feeding the fabric from the hemmer and past the trim ming mechanism.

HORACE l'. GRUMAN. 

